In the United States, half of all women will experience an unintended pregnancy by age 45. 1, 2 among younger women, by the age of 20, more than 30% will experience a pregnancy, and over 80% of these pregnancies will be unintended. 1 Unwanted births are associated with negative physical, social and economic consequences for both the woman and her child. 3-5 Ensuring that a woman is able to make the right choice for herself about whether to carry an unintended pregnancy to term is fundamental to her health and wellbeing. Decisions regarding unintended pregnancy have ramifications that affect a woman's educational, professional and personal aspirations, as well as her current and future family life. 6, 7 the importance of social support - from partners, parents and friends - for a woman's decision to carry an unintended pregnancy to term has been identified in previous work, 8-11 but the dynamic nature of this support and the various forms it can take have been under-studied. Particularly, few studies have examined the influence of intimate, sexual relationships on the pregnancy resolution decision. This proposed study aims to 1) identify dynamics of intimate, sexual relationships that predict whether a woman will choose to carry an unintended pregnancy to term during her early adulthood (ages 18-22 years), and any delays in that decision; and 2) describe the needs for decision- making support perceived by young women faced with an unintended pregnancy. Combined, these two aims will provide insight into the overall influence of social support on pregnancy decision-making in young women, with the ultimate goal of helping health professionals address these influences during their counseling - including how to empower women to access the social support that they need, as well as ensuring that their informational needs are met. This enhanced support should reduce costly delays in pregnancy decision- making (financial and medical), and improve women's satisfaction with their choice. For Aim 1, the data will be derived from two and a half years of extensive weekly survey interviews with 196 young women ages 18-22 years who experienced 233 unintended pregnancies during their enrollment in the NICHD-funded Relationship Dynamics and Social Life (RDSL) Study. Logistic regression and marginal structural modeling will be used to explore the influence of relationship dynamics on pregnancy resolution. For Aim 2, the Principal Investigator will collect new qualitative data from in-depth interviews conducted among 25 women drawn from the original sample of 196 RDSL participants. Qualitative methods will be used to analyze interview data to contextualize results from quantitative analyses and to generate hypotheses for future post-doctoral research. The training program that I propose in this application will allow me to not only develop the quantitative and qualitative methodological skills to carry out my dissertation research, but will also help me to obtain the necessary professional skills that I will need for an active career as an independent, academic researcher.